Project Summary/Abstract Recently it has been reported that canines can detect the presence of colon cancer from the scent of exhaled breath, with 91% selectivity and 99% specificity (Sonoda, H. et al., Gut, 2011, 60, 814). The prospect of a device which can perform similarly opens the prospect of a rapid, non-invasive, accurate and inexpensive breath test for colon cancer. The iSense Medical Corp. (IMC) sensor operates analogously to biological olfaction in that a diverse array of cross- reactive chemical sensors is activated by the breath sample. Prior work has shown this sensor system, based on colorimetric indicators embedded in a nanoporous sol-gel matrix of very high surface area, to be capable of discrimination of complex mixtures (Suslick, B. et al., Anal. Chem. 2010, 82, 2067), and has recently been shown in clinical testing at the Cleveland Clinic Foundation (CCF) to detect the presence of lung cancer from exhaled breath, across stages, with accuracy of 85% (Mazzone, P. et al., J. Thoracic Oncology, in press). Under this contract we propose to customize the nanoporous indicator array to optimize its sensitivity to small molecule metabolites of active colon tumor, and in Phase 2 conduct a pilot study at CCF to quantify accuracy of detection of colon cancer from breath, by stage. PUBLIC HEALTH RELEVANCE: Project Narrative The proposed research effort will develop a rapid, inexpensive and non-invasive diagnostic test for the presence of colon cancer, as a prompt for subsequent colonoscopic examination. A further application of this technology would be a breath test to non-invasively and inexpensively monitor the efficacy of chemotherapy treatment.